1. Field of the Invention
The present invention relates to a method for controlling a low-power state in a mobile handset; and, more particularly, to a method for controlling a low-power state in a mobile handset that can provide a low-power state disconnected with a mobile communication network by inactivating a mobile communication function through manipulation of a user and controlling a control clock.
This work was supported by the Information Technology (IT) research and development program of the Korean Ministry of Information and Communication (MIC) and the Korean Institute for Information Technology Advancement (IITA) [2005-S-017-02, “Integrated Development of Ultra Low Power RF/HW/SW SoC”].
2. Description of Related Art
In present invention, a mobile handset is a potable terminal capable of transmitting/receiving voice, messages and video data through a mobile communication network, such as a Personal Communication Service (PCS) terminal, a Personal Digital Assistant (PDA), a smart phone, an International Mobile Telecommunication 2000 (IMT-2000) terminal, a wireless local area network (LAN) terminal.
FIGS. 1 to 2 illustrate state machines of a conventional mobile handset.
As shown in FIG. 1, the state machine of the conventional mobile handset includes a power-off state 100 in which power is not supplied and an active state 110 in which power is supplied and functions are activated.
As shown in FIG. 2, the active state 110 includes a traffic state 111, an access state 112, an idle state and a sleep state 114.
Each of states is shifted by users' manual or control of a power manager which pre-programmed corresponding to the current state of the mobile handset.
In case of Qualcomm MSM 6000 series modem processor, the traffic state 111, the access state 112, the idle state 113 and the sleep state 114 are operated by a 150 MHz control clock.
In addition, the sleep state 114 is a power-saving mode periodically searching a specific slot of a paging channel in predetermined time. In case of a Code Division Multiple Access (CDMA) system, a cycle of one slot is 1.28 seconds and one cycle includes 16 slots. After all, there are a total of 128 cycles and 2048 slots and the CDMA system enters the power-saving mode by setting up an index value for the cycle of slot. The power-saving mode is provided in a Wideband Code Division Multiple Access (WCDMA) and a Global System for Mobile communication (GSM) similarly to the power-saving mode of the CDMA system.
The user of the conventional mobile handset turns off the power of the handset or converts the mode of the handset to a manners mode, e.g., vibration or silence, when the user is in a public place such as a conference room or a theater.
When the power of the conventional mobile handset is turned off, additional functions such as watch, address management, schedule management, camera, voice recording and music playing cannot be provided to the user, and urgent call cannot be received.
In addition, when the user converts the mode of the conventional mobile handset to the manners mode to use the additional functions or not to miss calls in the public place, the user does not answer the received call due to awareness of the public place or hangs off the received call immediately. Actually, though the user does not use the mobile communication function, the power of the mobile handset is consumed for maintaining access to the mobile communication network, and the user is exposed to unnecessarily received calls.